Ensure we never try to register for the object id "NULL"

sync/android/java/src/org/chromium/sync/internal_api/pub/base/ModelType.java

Index: sync/android/java/src/org/chromium/sync/internal_api/pub/base/ModelType.java
diff --git a/sync/android/java/src/org/chromium/sync/internal_api/pub/base/ModelType.java b/sync/android/java/src/org/chromium/sync/internal_api/pub/base/ModelType.java
index a7d4797680fbdc301524d57ac38caa9a86aef026..028f53fc318f0885cfa3e0fa2f3b6e4a509ac30d 100644
--- a/sync/android/java/src/org/chromium/sync/internal_api/pub/base/ModelType.java
+++ b/sync/android/java/src/org/chromium/sync/internal_api/pub/base/ModelType.java
@@ -63,7 +63,7 @@ public enum ModelType {
     /**
      * A proxy tabs object (placeholder for sessions).
      */
-    PROXY_TABS("NULL"),
+    PROXY_TABS("NULL", true),
     /**
      * A favicon image object.
      */
@@ -80,8 +80,15 @@ public enum ModelType {
 
     private final String mModelType;
 
-    ModelType(String modelType) {
+    private final boolean mNonInvalidationType;
+
+    ModelType(String modelType, boolean nonInvalidationType) {
         mModelType = modelType;
+        mNonInvalidationType = nonInvalidationType;
+    }
+
+    ModelType(String modelType) {
+        this(modelType, false);
     }
 
     public ObjectId toObjectId() {
@@ -141,4 +148,14 @@ public enum ModelType {
         }
         return objectIds;
     }
+
+    public static Set<ModelType> stripNonInvalidationTypes(Set<ModelType> modelTypes) {

[Yaron, 2013/08/08 01:52:16]

Pleaes add Javadoc.

[nyquist, 2013/08/08 17:59:28]

Removed.

+        Set<ModelType> result = new HashSet<ModelType>(modelTypes);

[Yaron, 2013/08/08 01:52:16]

Which a name of "strip..." it's not clear why you're performing a copy. I also
think it's unnecessary.

[nyquist, 2013/08/08 17:59:28]

Removed.

+        for (ModelType modelType : values()) {
+            if (modelType.mNonInvalidationType) {
+                result.remove(modelType);
+            }
+        }
+        return result;
+    }
 }